We have used the z-scan technique at a wavelength (532 nm) near the transmission window of bulk gold to measure the nonlinear absorption coefficient of continuous approximately 50-Å-thick gold films, deposited onto surface-modified quartz substrates. For highly absorbing media such as metals, we demonstrate that determination of either the real or imaginary part of the third-order susceptibility requires a measurement of both nonlinear absorption and nonlinear refraction, i.e., both open- and closed-aperture z scans must be performed. Closed-aperture z scans did not yield a sufficient signal for the determination of the nonlinear refraction. However, open-aperture z scans yielded values ranging from β=1.9×10−3 to 5.3×10−3cm/W in good agreement with predictions which ascribe the nonlinear response to a Fermi smearing mechanism. We note that the sign of the nonlinearity is reversed from that of gold nanoparticle composites, in accordance with the predictions of mean field theories.

1.
D.
Ricard
,
P.
Rousignol
, and
C.
Flytzanis
,
Opt. Lett.
10
,
511
(
1985
).
2.
H. B.
Liao
,
R. F.
Xiao
,
J. S.
Fu
,
P.
Yu
,
G. K. L.
Wong
, and
P.
Sheng
,
Appl. Phys. Lett.
70
,
1
(
1997
).
3.
D. D.
Smith
,
G.
Fischer
,
R. W.
Boyd
, and
D. A.
Gregory
,
J. Opt. Soc. Am. B
14
,
1625
(
1997
).
4.
K.
Puech
,
W.
Blau
,
A.
Grund
,
C.
Bubeck
, and
G.
Cardenas
,
Opt. Lett.
20
,
1613
(
1995
).
5.
M. J.
Bloemer
,
J. W.
Haus
, and
P. R.
Ashley
,
J. Opt. Soc. Am. B
7
,
790
(
1990
).
6.
F.
Hache
,
D.
Ricard
,
C.
Flytzanis
, and
U.
Kreibig
,
Appl. Phys. A: Solids Surf.
47
,
347
(
1988
).
7.
K. L. Chopra, Thin Film Phenomena (McGraw-Hill, New York, 1969), p. 163.
8.
P. A.
DiMilla
,
J. P.
Folkers
,
H. A.
Biebuyek
, and
G. M.
Whitesides
,
J. Am. Chem. Soc.
117
,
2225
(
1994
).
9.
C. V.
Fragstein
and
H.
Romer
,
Z. Phys.
151
,
54
(
1958
).
10.
T.
Kim
,
R. M.
Crooks
,
M.
Tsen
, and
L.
Sun
,
J. Am. Chem. Soc.
117
,
3963
(
1995
).
11.
C. A.
Goss
,
D. H.
Charych
, and
M.
Majda
,
Anal. Chem.
63
,
85
(
1991
).
12.
M.
Sheik-Bahae
,
A. A.
Said
,
T.
Wei
,
D. J.
Hagan
, and
E. W.
Van Stryland
,
IEEE J. Quantum Electron.
26
,
760
(
1990
).
13.
J. A.
Giordmaine
and
J. A.
Howe
,
Phys. Rev. Lett.
11
,
207
(
1963
).
14.
E. Palik, Handbook of Optical Constants of Solids (Academic Press, Orlando, FL, 1985), p. 286.
15.
M. L.
Theye
,
Phys. Rev. B
2
,
3060
(
1970
).
16.
L. B.
Valdes
,
Proc. IRE
42
,
420
(
1954
).
17.
P.
Sheng
,
Phys. Rev. Lett.
45
,
60
(
1980
).
This content is only available via PDF.
You do not currently have access to this content.